Residential load centers in the form of rectangular circuit breaker enclosures electrically connect with the wire conductors within the electrical distribution cables by means of cable access openings formed in the top or bottom ends of the enclosures. Commercial panelboards that house industrial-rated circuit breakers also connect with the electrical power distribution cables by means of openings provided at either end of the enclosures. One such panelboard is described, for example, in U.S. Pat. No. 4,783,718. Once the wire conductors are connected with the circuit breakers within the load center or panelboard enclosures, cable retainer clamps are employed to provide strain relief to the cables. In the absence of the strain relief clamps, longitudinal forces applied to the cables could loosen the connections between the wire conductors and the circuit breakers.
Canadian Patent No. 658,727 describes a spring-like metal clamp arranged on the interior of an electrical outlet box to trap the electrical cable within the box and thereby provide strain relief function. A more recent cable clamp attachment for electrical outlet boxes is found within U.S. Pat. No. 4,591,658 wherein a spring-like plastic clamp in the vicinity of the cable access holes clamps the electrical cables against the side walls of the outlet boxes.
U.S. Pat. No. 4,922,056 describes an electrical box which includes means for securing sheathed cables to the base of the box. In this arrangement, a plurality of clamping jaws are attached to corresponding mounting bases by means of machine screws. The sheathed cables are trapped between the clamping jaws and the mounting bases to provide effective strain relief.
Canadian Patent 2,021,389 describes a means of fastening electrical cables to electrical panelboards employing a removable plastic plug that cooperates with the cable access slot to provide strain relief.
A primary object of this invention is to provide a simple, economic cable clamp adapter which requires no screws for providing strain relief to the cable.